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The role of hydrogen on the behavior of intergranular cracks in bicrystalline a-fe nanowires

Journal Article


Abstract


  • Hydrogen embrittlement (HE) has been extensively studied in bulk materials. However, little is known about the role of H on the plastic deformation and fracture mechanisms of nanoscale materials such as nanowires. In this study, molecular dynamics simulations are employed to study the influence of H segregation on the behavior of intergranular cracks in bicrystalline α-Fe nan-owires. The results demonstrate that segregated H atoms have weak embrittling effects on the pre-dicted ductile cracks along the GBs, but favor the cleavage process of intergranular cracks in the theoretically brittle directions. Furthermore, it is revealed that cyclic loading can promote the H accumulation into the GB region ahead of the crack tip and overcome crack trapping, thus inducing a ductile-to-brittle transformation. This information will deepen our understanding on the experi-mentally-observed H-assisted brittle cleavage failure and have implications for designing new nanocrystalline materials with high resistance to HE.

Publication Date


  • 2021

Citation


  • Li, J., Lu, C., Wang, L., Pei, L., Godbole, A., & Michal, G. (2021). The role of hydrogen on the behavior of intergranular cracks in bicrystalline a-fe nanowires. Nanomaterials, 11(2), 1-15. doi:10.3390/nano11020294

Scopus Eid


  • 2-s2.0-85099809008

Start Page


  • 1

End Page


  • 15

Volume


  • 11

Issue


  • 2

Abstract


  • Hydrogen embrittlement (HE) has been extensively studied in bulk materials. However, little is known about the role of H on the plastic deformation and fracture mechanisms of nanoscale materials such as nanowires. In this study, molecular dynamics simulations are employed to study the influence of H segregation on the behavior of intergranular cracks in bicrystalline α-Fe nan-owires. The results demonstrate that segregated H atoms have weak embrittling effects on the pre-dicted ductile cracks along the GBs, but favor the cleavage process of intergranular cracks in the theoretically brittle directions. Furthermore, it is revealed that cyclic loading can promote the H accumulation into the GB region ahead of the crack tip and overcome crack trapping, thus inducing a ductile-to-brittle transformation. This information will deepen our understanding on the experi-mentally-observed H-assisted brittle cleavage failure and have implications for designing new nanocrystalline materials with high resistance to HE.

Publication Date


  • 2021

Citation


  • Li, J., Lu, C., Wang, L., Pei, L., Godbole, A., & Michal, G. (2021). The role of hydrogen on the behavior of intergranular cracks in bicrystalline a-fe nanowires. Nanomaterials, 11(2), 1-15. doi:10.3390/nano11020294

Scopus Eid


  • 2-s2.0-85099809008

Start Page


  • 1

End Page


  • 15

Volume


  • 11

Issue


  • 2